Method of performing proximity discovery for network entity and user equipment

ABSTRACT

A method of performing proximity discovery for a network entity and a user equipment (UE). In one of the exemplary embodiments, this disclosure is directed to a generating method that is applicable to a network entity and includes at least but not limited to receiving a discovery request message comprising a ProSe application identifier (ID) and a UE identity, obtaining a discover code for performing the proximity discovery according to a target group of the UE identity, and transmitting a discovery response message comprising the discovery code in response to the discovery request message. The ProSe application ID indicates the target group of the UE identity.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of U.S. provisionalapplication Ser. No. 62/101,373, filed on Jan. 9, 2015. The entirety ofthe above-mentioned patent application is hereby incorporated byreference herein and made a part of specification.

BACKGROUND OF THE DISCLOSURE

1. Field of the Disclosure

The present disclosure generally relates to a method of performingproximity discovery for a network entity and a user equipment (UE).

2. Description of Related Art

In the field of device to device (D2D) communication which is oftenreferred to as a Proximity-based Services (ProSe) communication, a UEtypically may discover another UE and subsequently performs D2Dcommunication with another UE with or without the assistance of a corenetwork such as an Evolved Packet Core (EPC). The aforementioned casesuch as discover another UE by using direct radio signal, withoutassistance of core network is called “direct discovery”. When aproximity discovery procedure occurs in direct discovery, an announcingUE and a monitoring UE may send discovery request to a network entitysuch as a ProSe function in the EPC network for announcing andmonitoring the proximity discovery, respectively. The ProSe Functioncould be thought of as a collective logical function that implementsnetwork related actions required for ProSe. The ProSe Function may playdifferent roles for each of the features of ProSe. Subsequently, themonitoring UE would check whether a match event occurred. An announcingUE could be a UE which announces certain information that could be usedby a UE in proximity that has permission to discover. A monitoring UEcould be a UE that monitors certain information of interest inproximities of announcing UEs.

There could be at least two kinds of ProSe direct discovery, namely anopen discovery and a restricted discovery. The open discovery maypredominate where there is no explicit permission that is needed fromthe UE being discovered, whereas the restricted discovery may only takeplace with explicit permissions from the UEs that are being discovered.For example, when a user wants to find his/her friends on a socialnetwork application, his/her device will likely perform the restricteddiscovery.

A direct discovery procedure may involve different types of discoverycodes. A discovery filter of Discovery Response message may containProSe application code and ProSe application mask, and a ProSeapplication code of Discovery Response message or PC5 discovery messagemay contain ProSe application code. The ProSe application code maycontain parameters not limited to public land mobile network (PLMN) IDof a ProSe function that assigned the ProSe application code and atemporary identity corresponding to the ProSe application ID name. TheProSe application code could be used by a monitoring UE for full orpartial matching of PC5 Discovery messages received on PC5 interface.The ProSe application ID name could be used for identifying applicationrelated information for the ProSe-enabled UE. The ProSe application maskis a bitmask provided by the ProSe function in order to allow themonitoring UE to perform full or partial matching of PC5 Discoverymessages received on the PC5 interface.

FIG. 1 shows a general call flow of a ProSe direct discovery procedurewhich is consistent with 3GPP TS 23.303 for example. In step S110,service authorization for ProSe direct services is performed for ProSedirect discovery. If the UE is authorized to announce, the UE wouldperform an announce request procedure (S130) to obtain a ProSeApplication Code to be announced over the PC5 interface upon a requestfor announcing from upper layers. In step S131, when the UE is triggeredto announce then it sends a discovery request for announcing to theProSe Function in Home PLMN (HPLMN). In step S135, if the request issuccessful and is provided with ProSe Application Code then it startsannouncing on PC5 interface. On the other hand, if the UE is authorisedto monitor, the UE (such as an announcing UE) would perform a monitorrequest procedure (S150) to receive and process PC5_DISCOVERY messagesupon a request for monitoring from upper layers. PC5_DISCOVERY messageis transmitted from an announcing UE to a monitoring UE. In step S151,when the UE (such as a monitoring UE) is triggered to monitor, it sendsa discovery request for monitoring to the ProSe Function. In step S155,if the request is successful and the UE is provided with a DiscoveryFilter consisting of ProSe Application Code(s) and/or ProSe ApplicationMask(s), the UE would start monitoring for these ProSe Application Codeson the PC5 interface. In step S170, when the monitoring UE detects thatone or more ProSe Application Code(s) that match the discovery filter,the UE would send a match report including the ProSe Application Code(s)to the ProSe Function. There is a match event when, for any of the ProSeApplication masks in a Discovery Filter, the output of a bitwise ANDoperation between the ProSe Application Code contained in thePC5_DISCOVERY message and this ProSe Application mask matches the outputof a bitwise AND operation between the ProSe Application mask and theProSe Application Code in the same discovery filter.

However, the aforementioned ProSe direct discovery procedure does notdescribe how the restricted discovery functions in detail as thediscovery codes assigned for the restricted discovery is not described.The assignment of the discovery codes would be very important for therestricted discovery because only the target UEs that an announcing UEwants to discover would achieve the match event. Accordingly, therewould be need to provide a method for assigning those discovery codesfor the restricted discovery and a restricted discovery procedure.

SUMMARY OF THE DISCLOSURE

Accordingly, the present disclosure is directed to a method ofperforming proximity discovery for a network entity and a UE.

In one of the exemplary embodiments, the present disclosure is directedto a method of performing proximity discovery which is used by a networkentity and the method may include not limited to receiving a discoveryrequest message comprising a ProSe application identifier (ID) and a UEidentity, obtaining a discover code for performing the proximitydiscovery according to a target group of the UE identity, andtransmitting a discovery response message comprising the discovery codein response to receiving the discovery request message. The ProSeapplication ID indicates the target group of the UE identity.

In one of the exemplary embodiments, the present disclosure is directedto a method of performing proximity discovery which is used by a UE andthe method may include not limited to transmitting a first PC5 DISCOVERYmessage comprising a first ProSe application code for a restricteddiscovery over a PC5 interface, wherein the PC5 interface is connectedbetween the UE and another UE, receiving a PC5 discovery responsemessage over the PC5 interface in response to the first PC5 DISCOVERYmessage, and determining whether a target-match event occurs accordingto the PC5 discovery response message.

In one of the exemplary embodiments, the present disclosure is directedto a method of performing proximity discovery which is used by a UE andthe method may include not limited to receiving a first PC5 DISCOVERYmessage of an announcing UE comprising a first ProSe application codefor a restricted discovery over a PC5 interface, wherein the PC5interface is connected between the UE and another UE, and transmitting aPC5 discovery response message corresponding to the announcing UE overthe PC5 interface in response to receiving the first PC5 DISCOVERYmessage.

In order to make the aforementioned features and advantages of thepresent disclosure comprehensible, exemplary embodiments accompaniedwith figures are described in detail below. It is to be understood thatboth the foregoing general description and the following detaileddescription are exemplary, and are intended to provide furtherexplanation of the disclosure as claimed.

It should be understood, however, that this summary may not contain allof the aspect and embodiments of the present disclosure and is thereforenot meant to be limiting or restrictive in any manner. Also the presentdisclosure would include improvements and modifications which areobvious to one skilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the disclosure, and are incorporated in and constitutea part of this specification. The drawings illustrate embodiments of thedisclosure and, together with the description, serve to explain theprinciples of the disclosure.

FIG. 1 shows a general call flow of a ProSe direct discovery procedure.

FIG. 2 is a schematic diagram illustrating a communication system inaccordance with an embodiment of the present disclosure.

FIG. 3 illustrates an exemplary UE in accordance with an embodiment ofthe present disclosure.

FIG. 4 illustrates an exemplary network entity in accordance with anembodiment of the present disclosure.

FIG. 5 is a flow chart illustrating method of performing proximitydiscovery for a UE in accordance with an embodiment of the presentdisclosure.

FIG. 6 is a flow chart illustrating method of performing proximitydiscovery for a UE in accordance with an embodiment of the presentdisclosure.

FIG. 7 illustrates a signaling diagram of a ProSe direct discoveryprocess in accordance with one of the exemplary embodiment of thepresent disclosure.

FIG. 8 illustrates a signaling diagram of a ProSe direct discoveryprocess in accordance with one of the exemplary embodiment of thepresent disclosure.

FIG. 9 is a flow chart illustrating method of performing proximitydiscovery for a network entity in accordance with an embodiment of thepresent disclosure.

FIG. 10 illustrates a signaling diagram of a monitor request process inaccordance with one of the exemplary embodiment of the presentdisclosure.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the present preferredembodiments of the disclosure, examples of which are illustrated in theaccompanying drawings. Wherever possible, the same reference numbers areused in the drawings and the description to refer to the same or likeparts.

The present disclosure would provide signalling message flows forrestricted direct discovery and an assignment method of discovery codessuch as a ProSe application code and a discovery filter. The proposedsignalling message flows would be compatible with a standard of D2Ddiscovery procedure such as a proximity direct discovery proceduredescribed at least in 3GPP TS 23.303 and TS 24.334 which areincorporated by reference herein. On the other hand, the proposed methodto handle the assignment of discovery code according to a ProSeapplication ID and an UE identity would achieve the requirement of bothopen and restricted discoveries. The ProSe application ID would indicatea target group of announcing UEs or monitoring UEs, an open discovery,or a restricted discovery. Reference will now be made to the presentpreferred embodiments of the disclosure, and it will be apparent tothose skilled in the art that adjustments and applications can becorrespondingly made to the following embodiments based on demandsinstead of being limited by the content in the following description.

FIG. 2 is a schematic diagram illustrating a communication system inaccordance with an embodiment of the present disclosure. Referring toFIG. 2, the communication system 200 could include but not limited toUEs 210 and 220, base stations (BSs) 230 and 240, core networks (CNs)250 and 270, and a APP server 290.

The term “user equipment” (UE) such as UEs 210 and 220 in thisdisclosure could represent various embodiments which for example couldinclude but not limited to a mobile station, an advanced mobile station(AMS), a server, a client, a desktop computer, a laptop computer, anetwork computer, a workstation, a personal digital assistant (PDA), atablet personal computer (PC), a scanner, a telephone device, a pager, acamera, a television, a hand-held video game device, a musical device, awireless sensor, and so like. In some applications, a UE may be a fixedcomputer device operating in a mobile environment, such as a bus, train,an airplane, a boat, a car, and so forth.

A UE may be represented by at least the functional elements asillustrated in FIG. 3 in accordance with an embodiment of the presentdisclosure. UE 210 may contain at least but not limited to atransmitting module 211, a receiving module 213, an analog-to-digital(A/D)/digital-to-analog (D/A) converter 214, a processing module 216,optionally a memory module 215, and one or more antenna units 212. Thetransmitting module 211 transmits downlink signals wirelessly, and thereceiving module 213 receives uplink signals wirelessly. Thetransmitting module 211 and the receiving module 213 may also performoperations such as low noise amplifying, impedance matching, frequencymixing, up or down frequency conversion, filtering, amplifying, and solike. The (A/D)/(D/A) converter 214 is configured to convert from ananalog signal format to a digital signal format during uplink signalprocessing and from a digital signal format to an analog signal formatduring downlink signal processing. The processing module 216 isconfigured to process digital signal and to perform procedures of theproposed proximity discovery method described in the following inaccordance with exemplary embodiments of the present disclosure. Also,the processing module 216 may optionally be coupled to a non-transitorymemory module 215 to store programming codes, device configurations, acodebook, buffered or permanent data, discovery codes such as ProSeapplication codes and discovery filters, ProSe application ID, and soforth. The functions of the processing module 216 could be implementedby using programmable units such as a micro-processor, amicro-controller, a DSP chips, FPGA, etc. The functions of theprocessing module 216 may also be implemented with separate electronicdevices or ICs, and the functions performed by the processing module 216may be implemented within the domain of either hardware or software.

UE 220 may contain not limited to a transmitting module 221, a receivingmodule 223, an A/D/D/A converter 224, a processing module 226,optionally a memory module 225, and one or more antenna units 222 (notshown). The UE 220 may have a similar or the same functional elements ofthe UE 210, and therefore detailed descriptions for each element willnot be repeated.

The term “base station” (BS) such as the BS 230 and 240 in thisdisclosure could represent various embodiments which for example couldinclude but not limited to a Home Evolved Node B (HeNB), an eNB, anadvanced base station (ABS), a base transceiver system (BTS), an accesspoint, a home base station, a relay station, a scatterer, a repeater, anintermediate node, an intermediary, and/or satellite-basedcommunications base stations.

The CNs 250 and 270 may be, for example, the, 2G CN such as GPRS corenetwork, 3G CN, or 4G CN such as Evolved Packet Core (EPC). The CN 250may contain at least but not limited to a mobility management entity(MME) 251, a Home Subscriber Server (HSS) 252, a network entity 254, aSecured User Plane Location Platform (SLP) 256, a Packet Data NetworkGateway (P-GW) 258, and a Serving Gateway (S-GW) 259. The MME 251 isconnected with the BS 230, the HSS 252, and the S-GW 259. The S-GW 259is connected with the MME 251 and the P-GW 258. The network entity 254is connected with the HSS 252, the SLP 256, and the APP server 290.Similarly, The CN 270 may contain at least but not limited to a MME 271,a HSS 272, a network entity 274, a SLP 276, a P-GW 278, and a S-GW 279.The coupling relation among the MME 271, the HSS 272, the network entity274, the SLP 276, the P-GW 278, and the S-GW 279 could be referred tothe coupling relation among the MME 251, the HSS 252, the network entity254, the SLP 256, the P-GW 258, and the S-GW 259, and therefore detaileddescriptions for each element will not be repeated.

The exemplary network entities 254 and 257 could be ProSe Functionswithin an EPC network. The network entity 254 may be represented by atleast the functional elements as illustrated in FIG. 4 in accordancewith an embodiment of the present disclosure. The network entity 254would include at least but not limited to a processing module 254_1, anA/D/D/A converter 254_3, a communication protocol module 254_4, atransmitting module 254_5, and a receiving module 254_7. Thetransmitting module 254_5 and the receiving module 254_7 is respectivelyused for transmitting and receiving modulated signals which could bewireless RF signals (through one or more antennas), optical signals, orsignals sent over a cable. The transmitting module 254_5 and thereceiving module 254_7 may also perform operations such as low noiseamplifying, impedance matching, frequency mixing, up or down frequencyconversion, filtering, amplifying, and so like.

The A/D/D/A converter 254_3 is configured to convert from an analogsignal format to a digital signal format during uplink signal processingand from a digital signal format to an analog signal format duringdownlink signal processing. The communication protocol module 254_4could be independent from or an inherent part of the processing module254_1 and would convert a digital message into a format that iscompatible with various interfaces such as PC2, PC3, PC4, PC4x, and soforth. Those functions performed by the communication protocol module254_4 may be implemented within the domains of either hardware orsoftware.

The processing module 254_1 is configured to process digital signal andto perform procedures of the proposed discovery code generating methoddescribed in the following in accordance with exemplary embodiments ofthe present disclosure. Also, the processing module 254_1 may optionallybe coupled to a non-transitory memory module 254_2 to store programmingcodes, device configurations, a codebook, buffered or permanent data,ProSe application codes, ProSe application masks, discovery filters,ProSe application IDs, discovery code combination maps, discovery codecombination pairs, discovery code combinations, allowed user lists, andso forth. The discovery code combination maps, the discovery codecombination pairs, and discovery code combinations would be describedlater. The functions of the processing module 254_1 could be implementedby using programmable units such as a micro-processor, amicro-controller, a DSP chips, FPGA, etc. The functions of theprocessing module 254_1 may also be implemented with separate electronicdevices or ICs, and functions performed by the processing module 254_1may also be implemented within the domains of either hardware orsoftware.

The network entity 274 may have a similar or the same functionalelements of the network entity 254, and therefore detailed descriptionsfor each element will not be repeated. In some other embodiment of thepresent disclosure, the network entities 254 and 274 would be anapplication (APP) server, a file server, a cloud server, a third partyserver, etc in (or not in) the CNs 250 and 270.

The APP server 290 could be a ProSe APP server, a file server, a cloudserver, etc. The APP server 290 further stores network level user IDssuch as EPC ProSe User IDs (EPUIDs), ALUIDs (such as ALUIDs of thediscoverees, ALUIDs of the discoverers), network entity IDs such asProSe function ID (PFID), and lists of application permissions of users(such as a allowed user list corresponding the ProSe application ID andthe UE identity).

It should be noticed that, the aforementioned communication system 200is assumed that the UEs 210 and 220 are belonged to the different CNssuch as the CNs 250 and 270, that means the UEs 210 and 220 transmit andreceive data or messages through the CNs 250 and 270, respectively. Insome other embodiment of the disclosure, the UEs 210 and 220 may locatedwithin a network coverage of the BS 230 (or the BS 240), and the UE 210and 220 both transmit and receive data or messages through the CN 250(or the CN 270).

In the following description, the embodiments of the present disclosurewould be consisted of two parts. The first part of the embodiments ofthe present disclosure would be the proposed signalling message flowsfor the restricted discovery. The second part of the embodiments of thepresent disclosure would be proposed assignment and management methodsfor discovery codes such as ProSe application codes and discoveryfilters contained in Discovery Response message which is consistent with3GPP TS 23.303 and TS 24.334.

FIG. 5 is a flow chart illustrating method of performing proximitydiscovery for a UE such as UEs 210 and 220 in accordance with anembodiment of the present disclosure. For convenience, in the followingdescription, UE 210 would be used for performing the proposed proximitydiscovery method. However, UE 220 may perform the same or similarprocedure as UE 210, and thus a repetition of descriptions will not berepeated.

In step S510, the processing module 216 of UE 210 may transmit a firstPC5 DISCOVERY message comprising a first ProSe application code for arestricted discovery over a PC5 interface through the transmittingmodule 211. The PC5 interface is connected between UE 210 and another UEsuch as UE 220.

Specifically, it is assumed that UE 210 would be an announcing UE, andUE 210 would perform a restricted discovery in order to discover somespecific UE such as monitoring UEs or UE 220. For example, UE 210 wantsto chat with UE 220 by a social network application. After UE 210performs an announce request procedure with the network entity 254 or274, UE 210 may receive the first ProSe application code contained inthe Discovery Response message. Then, UE 210 may announce over the PC5interface by transmitting the first PC5 DISCOVERY message comprising thefirst ProSe application code upon a request for announcing from upperlayers such as an application layer. The PC5 DISCOVERY message maycontain parameters not limited to ProSe application code and MessageIntegrity Check (MIC) associated with the ProSe application code.

It should be noticed that, PC5 interface is reference point betweenProSe-enabled UEs such as UEs 210 and 220 used for control and userplane for ProSe Direct Discovery, ProSe Direct Communication and ProSeUE-to-Network Relay.

In step S530, the processing module 216 may receive a PC5 discoveryresponse message over the PC5 interface through the receiving module 213in response to the first PC5 DISCOVERY message. In a ProSe directdiscovery procedure which is consistent with 3GPP TS 23.303 and TS24.334 for example, after receiving the first PC5_DISCOVERY message ofthe UE 210, a monitoring UE such as UE 220 may check whether the firstProSe application code matches discovery filters stored in UE 220, andtransmit Match Report message to the network entity 274 or 254 if thefirst ProSe application code matches the discovery filters. The MatchReport message may contain parameters not limited to the first ProSeapplication code which is matched with the discovery filter and a UE IDsuch as International Mobile Subscriber Identity (IMSI). However, UE 210would not directly receive response from the monitoring UE over PC5interface in response to the PC5 DISCOVERY message. In this embodimentof the present disclosure, UE 210 would receive one or more PC5discovery response messages from the monitoring UE over PC5 interface.

In step S550, the processing module 216 may determine whether atarget-match event occurs according to the PC5 discovery responsemessage.

Specifically, in this embodiment, if the first ProSe application codematches discovery filters stored in the monitoring UE, the monitoring UEwould transmit a PC5 discovery response message to UE 210. Then, if UE210 receives the PC5 discovery response message, the processing module216 would determine that the target-match event occurs. That means themonitoring UE who transmits the PC5 discovery response message would bethe targeted UE of UE 210 in this restricted discovery. On the otherhand, if the first ProSe application code does not match discoveryfilters stored in the monitoring UE, one or more monitoring UE would nottransmit a discovery response message to UE 210. Then, if UE 210 doesnot receive the PC5 discovery response message, the processing module216 would determine that the target-match event may not occur. Thatmeans the monitoring UEs who does not transmit the discovery responsemessage would not be the targeted UE of UE 210 in this restricteddiscovery.

In another embodiment of the present disclosure, the PC5 discoveryresponse message is a second PC5 DISCOVERY message of a monitoring UE.The processing module 216 may determine the target-match eventcorresponding to a second ProSe application code of the second PC5DISCOVERY message occurs in response to the second ProSe applicationcode as being matched with the monitoring UE, and determine thetarget-match event corresponding to the second ProSe application code ofthe second PC5 DISCOVERY message does not occurs in response to thesecond ProSe application code as being not matched with the monitoringUE.

Specifically, in this embodiment, in response to receiving the first PC5DISCOVERY message, the monitoring UEs would determine whether the firstPC5 DISCOVERY message is in monitoring lists of the monitoring UEs. Forexample, the monitoring UEs may check whether public land mobile network(PLMN) ID of the first ProSe application code contained in the first PC5DISCOVERY message is in the monitoring list. Then, the monitoring UEsmay transmit the second PC5 DISCOVERY message comprising the secondProSe application code if the first PC5 DISCOVERY message is inmonitoring lists of the monitoring UEs. If UE 210 receives the secondPC5 DISCOVERY message, the processing module 216 would check whether thesecond ProSe application code is matched. For example, the processingmodule 216 would check whether the second ProSe application code matchesone or more discovery filters stored in UE 210. If the second ProSeapplication code is matched, UE 210 would determine the target-matchevent occurs, and UE 210 may perform a match report procedure with thenetwork entity 254 or 274 which is consistent with 3GPP TS 23.303 and TS24.334. That means the monitoring UE who has the second ProSeapplication code matched in the target-match event would be the targetedUE of UE 210 in this restricted discovery. On the other hand, if thesecond ProSe application code is not matched, UE 210 would determine thetarget-match event does not occur, and UE 210 may cancel or disable thematch report procedure with the network entity 254 or 274. That meansthe monitoring UEs who has the unmatched second ProSe application codewould not be the targeted UE of UE 210 in this restricted discovery.

It should be noticed that, after receiving the second PC5 DISCOVERYmessage, the processing module 216 may obtain the discovery filterswhich have been stored in the memory module 215. In some example, theprocessing module 216 may further perform a monitor request procedurewhich is consistent with 3GPP TS 23.303 and TS 24.334, to obtain one ormore discovery filters.

The aforementioned embodiment would be applied for the announcing UE.Subsequently, another proposed method of performing proximity discoveryfor the restricted discovery would be applied for the monitoring UE inthe following description. FIG. 6 is a flow chart illustrating method ofperforming proximity discovery for a UE such as UEs 210 and 220 inaccordance with an embodiment of the present disclosure. Forconvenience, in the following description, UE 220 would be used forperforming the proposed proximity discovery method. However, UE 210 mayperform the same or similar procedure as UE 220, and thus a repetitionof descriptions will not be repeated.

In step S610, the processing module 226 of UE 220 may receive a thirdPC5 DISCOVERY message of an announcing UE comprising a third ProSeapplication code for a restricted discovery over the PC5 interfacethrough the transmitting module 221. In this embodiment, it is assumedthat UE 220 is a monitoring UE, and an announcing UE such as UE 210would perform a restricted discovery in order to discover some specificUE such as monitoring UEs or UE 220. The further detailed description ofthe step S610 may be referred to the description of the step 510 of FIG.5, and therefore detailed description will not be repeated. The PC5interface is connected between UE 220 and another UE such as UE 210.

In step S630, the processing module 226 may transmit a PC5 discoveryresponse message corresponding to the announcing UE over the PC5interface through the transmitting module 221 in response to receivingthe third PC5 DISCOVERY message. In one embodiment of the presentdisclosure, UE 220 may check whether the third ProSe application codematches stored discovery filters. Specifically, if the third ProSeapplication code matches the stored discovery filters, UE 220 wouldtransmit the PC5 discovery response message indicating that thetarget-match event occurs. Subsequently, UE 220 may perform a matchreport procedure with the network entity 274 or 254 which is consistentwith 3GPP TS 23.303 and TS 24.334. That means UE 220 who transmits thePC5 discovery response message would be the targeted UE of UE 210 inthis restricted discovery. On the other hand, in response to the thirdProSe application code not matching the stored discovery filters, UE 220would not transmit the PC5 discovery response message. That means UE 220who does not transmit the PC5 discovery response message would not bethe targeted UE of UE 210 in this restricted discovery.

In one embodiment of the present disclosure, the PC5 discovery responsemessage is a fourth PC5 DISCOVERY message of UE 220, and UE 220 maytransmit the fourth PC5 DISCOVERY message comprising a fourth ProSeapplication code to UE 210 in response to receiving the third PC5DISCOVERY message. In this embodiment, in response to receiving thethird PC5 discovery message, UE 220 would determine whether the thirdPC5 DISCOVERY message is in monitoring lists of the monitoring UEs. Forexample, UE 220 may check whether the third ProSe application codecontained in the third PC5 DISCOVERY message is in the monitoring list.Then, in response to the third PC5 DISCOVERY message being in monitoringlists of UE 220, UE 220 would become an announcing UE, and prepare tosend announcing message such as the fourth PC5 DISCOVERY message.Subsequently, the fourth PC5 DISCOVERY message comprising the fourthProSe application code would be transmitted over PC5 interface by UE220.

It should be noticed that, after receiving the third PC5 DISCOVERYmessage, the processing module 226 may obtain the fourth applicationcode which have been stored in the memory module 225. In some example,the processing module 226 may further perform a announce requestprocedure which is consistent with 3GPP TS 23.303 and TS 24.334, toobtain the fourth application code. In addition, the first, second,third and fourth PC5 DISCOVERY messages may be PC5_DISCOVERY messageswhich is consistent with 3GPP TS 24.334, or any PC5 Control Protocolmessages. The PC5 discovery response messages may be PC5_DISCOVERYmessages which is consistent with 3GPP TS 24.334, or any PC5 ControlProtocol messages.

In order to help those skilled in the art to understand how the proposedmethods of proximity discovery are processed in the communication system200 according to the embodiments of the present disclosure, thefollowing would provide two examples for different scenarios.

In the first example, FIG. 7 illustrates a signaling diagram of a ProSedirect discovery process in accordance with one of the exemplaryembodiment of the present disclosure. In this scenario, it is assumedthat UE 710 is an announcing UE, and UE 720 and 730 are monitoring UEs.UE 710 and UE 720 are friends, but UE 710 and UE 730 are not friends. UE710 would like to find its friends for chatting. In step S711, UE 710starts announcing ProSe application code of a restricted discoveryobtained from a ProSe function by transmitting PC5 DISCOVERY messagecomprising the ProSe application code over PC5 interface. This ProSeapplication code would match with UE 720 but not with UE 730. Then, UEs720 and 730 may receive the PC5 Discovery message transmitted by UE 710.In step S713, UE 720 would check whether the ProSe application code ofUE 710 contained in the PC5 DISCOVERY message matches discovery filterwhich obtain from the ProSe function. A match event occurs in UE 720because the ProSe application code matches with UE 720, then UE 720would transmit PC5 Discovery response message to UE 710 (S717). UE 710would be noticed that its friend UE 720 is nearby and may want to chatwith UE 710. On the other hand, in step S715, UE 730 would also checkwhether the ProSe application code contained in the PC5 DISCOVERYmessage matches discovery filter of UE 730 which obtain from the ProSefunction. However, a match event would not occur in UE 730 because theProSe application code does not match with UE 730, then UE 730 would nottransmit PC5 Discovery response message to UE 710.

In the second example, FIG. 8 illustrates a signaling diagram of a ProSedirect discovery process in accordance with one of the exemplaryembodiment of the present disclosure. In this scenario, it is assumedthat UE 810 and UE 820 are friends, but UE 810 and UE 830 are notfriends. UE 810 would like to find its friends for chatting. In stepS811, UE 810 starts announcing a fifth ProSe application code of arestricted discovery obtained from a ProSe function by transmitting afifth PC5 DISCOVERY message comprising the fifth ProSe application codeover PC5 interface. This fifth ProSe application code would inmonitoring lists of UE 820 and 830. Then, UEs 820 and 830 may receivethe fifth PC5 DISCOVERY message transmitted by UE 810. In step S813, UE830 would transmit a sixth PC5 DISCOVERY message comprising a sixthProSe application code. After receiving the sixth PC5 DISCOVERY message,UE 810 would determine that the sixth ProSe application code is notmatched because UE 810 is not UE 830's target (Step S815). On the otherhand, in step S817, UE 820 would transmit a seventh PC5 DISCOVERYmessage comprising a seventh ProSe application code. After receiving theseventh PC5 DISCOVERY message, UE 810 would determine that the seventhProSe application code is matched because UE 820 is UE 830's target(Step S819). Then, UE 810 may perform a match report procedure with theProSe function using the third ProSe application code.

In the aforementioned embodiments, the announcing UE would announceProSe application code for restricted discovery, and the announced ProSeapplication code may only match with specific discovery filters. In thefollowing embodiments, the proposed method for assigning and maintainingdiscovery codes such as ProSe application code and discovery filter ofopen discovery and restricted discovery would be introduced.

At first, several parameters would be defined for the followingembodiments. ProSe application codes Pr and Po may contain inPC5_DISCOVERY messages for announcing. ProSe application masks Mm and Mnand ProSe application code A may contain in discovery filters. It isassumed that ProSe application code Pr may match with a discovery filtercomprising ProSe application mask Mm, but may not match with anotherdiscovery filter comprising ProSe application mask Mn. And, ProSeapplication code Po may match with a discovery filter comprising ProSeapplication mask Mm, and may also match with another discovery filtercomprising ProSe application mask Mn.

A discovery code combination such as a restricted announcing combination(RAC) may contain parameters not limited to a set of ProSe applicationcode Pr, ProSe application code A, and ProSe application mask Mn. Adiscovery code combination pair such as a restricted announcing ProSeapplication pair (RAPAP) may contain parameters not limited to a set ofProSe application ID and RAC. Each ProSe application ID may correspondto different target groups. For example, ProSe application ID Aindicates a family group of social network application A, ProSeapplication ID B indicates a classmate group of social networkapplication B, and ProSe application IDs A and B may be different. Adiscovery code combination map such as a restricted announcing ProSeapplication map (RAPAM) may contain parameters not limited to all RAPAPsthat belong to a specific announcing UE.

For example, table (1) is an example of RAPAM of UE X. RAC1 and RAC2 arecorresponding to ProSe application ID ID1 and ID2, respectively.

TABLE (1) ProSe application ID RAC ID1 RAC1 ID2 RAC2

It should be noticed that, the network entities 254 and 274 may storeand maintain RAPAMs for all its served UEs such as UE 210 and 220. Inaddition, RAPAMs stored in the network entities 254 and 274 may becorrespond to one or more UEs which is in an allowed user list of eachmonitoring UE. The allowed user list may contain UEs allowed to discoverthe monitoring UE such as UE 220, and each allowed user list may becorresponding to different target groups of monitoring UEs. For example,allowed user list A is corresponding to family group of UE 210, alloweduser list B is corresponding to colleague group of UE 210, and alloweduser list C is corresponding to classmate group of UE 210. The alloweduser list may be requested by the network entity 254 or 274, to ask theAPP server 290 or other third party server for the discovery policies ofthe monitoring UEs. The monitoring UE may configure its discovery policyon website or application through Internet. For example, UE 220 mayconfigure that “can be discovered by family” and “can not be discoveredby classmate” through installed social application F in response toreceiving a setting operation of user of UE 220.

FIG. 9 is a flow chart illustrating method of performing proximitydiscovery for a network entity such as the network entities 254 and 274in accordance with an embodiment of the present disclosure. Forconvenience, in the following description, the network entity 254 wouldbe used for performing the proposed proximity discovery method. However,the network entity 274 may perform the same or similar procedure as thenetwork entity 254, and thus a repetition of descriptions will not berepeated. In step S910, the processing module 254_1 of the networkentity 254 may receive a discovery request message comprising a ProSeapplication ID and a UE identity through the receiving module 254_7. TheProSe application ID indicates a target group of the UE identity.

Specifically, in an announce request procedure which is consistent with3GPP TS 23.303 and TS 24.334, an announcing UE such as UE 210 maytransmit a Discovery Request message to the network entity 254 or thenetwork entity 274 in HPLMN. The discovery request message may containparameters not limited to a ProSe application ID, a UE identity, anannounce command, and application ID. The ProSe Application ID indicateswhat UE such as UE 210 is interested to announce and what target groupis interested to be discovered. The UE 210 or 220 is configured with thedata structure of the ProSe Application IDs corresponding to HPLMN. TheUE Identity is set to e.g. International Mobile Subscriber Identity(IMSI). The IMSI is consists of a mobile country code (MCC), a mobilenetwork code (MNC), and a Mobile Subscriber Identification Number(MSIN). The Application ID represents a unique identifier of the UEapplication that has triggered the transmission of the Discovery Requestmessage.

On the other hand, in a monitor request procedure which is consistentwith 3GPP TS 23.303 and TS 24.334, a monitoring UE such as UE 220 mayalso transmit a Discovery Request message comprising ProSe applicationID, UE identity, monitor command, application ID to the network entity274 or the network entity 254 in HPLMN. The ProSe Application IDindicate what UE such as UE 220 is interested to monitor and what targetgroup would be allowed to discover, and the ProSe Application ID isconsist a subset of the data structure of the PLMN. Then, the processingmodule 254_1 may receive the Discovery Request message from theannouncing UE(s) or the monitoring UE(s) through the receiving module254_7.

In step S930, the processing module 254_1 may obtain a discover code forperforming the proximity discovery according to the target group of theUE identity. Specifically, the processing module 254_1 may check for theauthorization of the application represented by the Application ID. Ifthe Discovery Request is authorized, then the ProSe Function 254 wouldcheck whether UE 210 or 220 is authorized to use the ProSe ApplicationID contained in the Discovery Request. If UE 210 or 220 is authorised touse that ProSe Application ID, then the processing module 254_1 wouldprepare for one or more discovery codes contained in a DiscoveryResponse message.

In one embodiment of the present disclosure, the discover code is aProSe application code of an announcing UE such as UE 210, and theprocessing module 254_1 would obtain the ProSe application code for anopen discovery or a restricted discovery according to the ProSeapplication ID. Specifically, the ProSe application ID may also indicatethat the announcing UE would like to use the open discovery or therestricted discovery. If an announcing UE requires for the opendiscovery, the processing module 254_1 would assign the ProSeapplication codes Po to this announcing UE. One the other hand, if theannouncing UE requires for the restricted discovery, the processingmodule 254_1 would assign the ProSe application code according to adiscovery code combination of the announcing UE corresponding to thetarget group of the UE identity in response to obtaining the ProSeapplication code for the restricted discovery. The processing module254_1 would check the discovery code combination map such as RAPAM ofthis announcing UE and determine whether the code combination such asRAC corresponding to the ProSe application ID is available.

Then, the processing module 254_1 may obtain the ProSe application codefrom the discovery code combination in response to the discovery codecombination corresponding to the ProSe application ID being available.For example, the processing module 254_1 may assign ProSe applicationcode Pr in a RAC corresponding to the ProSe application ID to UE 210. Onthe other hand, the processing module 254_1 may generate a firstdiscovery code combination and assigning an eighth ProSe applicationcode in the first discovery code combination as the ProSe applicationcode in response to the discovery code combination corresponding to theProSe application ID being not available. For example, the processingmodule 254_1 may create a new RAC of the ProSe application ID, andassign ProSe application code Pr in the created RAC to UE 210. Then, thecreated RAC would be updated and corresponding to ProSe application IDcontained in the Discovery Request message to RAPAM of UE 210.

It should be noticed that, another information element in the DiscoveryRequest message would also indicate whether the announcing UE want touse open or restricted discovery. For example, Discovery Type ofinformation element which is consistent with 3GPP TS 24.334.

In one embodiment of the present disclosure, the discover code comprisesone or more discovery filters of a monitoring UE, and the processingmodule 254_1 may assign a ProSe application code of the monitoring UEand a ProSe application mask to each discovery filter according to oneor more discovery code combinations of one or more allowed users in thetarget group, respectively. Specifically, if the Discovery Requestmessage is requested by a monitoring UE, the processing module 254_1would assign discovery filter to this monitoring UE. The processingmodule 254_1 may obtain an allowed user list such as relationship listof the monitoring UE corresponding to the request ProSe application IDcontained in the Discovery Request message.

It is assumed that allowed user list is defined as S_(allowed). Theallowed user list S_(allowed) may comprise one or more allowedapplication layer user IDs, UE identities, or any identifiers of allowedusers. The processing module 254_1 would obtain the discovery filter foreach allowed user. For every allowed user in the allowed user listS_(allowed), the processing module 254_1 may prepare a discovery filterF and start to assign ProSe application mask to each discovery filter F.Then, the processing module 254_1 may check whether a RAC of eachallowed user corresponding to the request ProSe application ID isavailable.

The processing module 254_1 may obtain a first ProSe application code ofthe monitoring UE and a first ProSe application mask from a firstdiscovery code combination of the allowed user in the discovery codecombination in response to the first discovery code combination of theallowed user corresponding to the ProSe application ID being available.For example, ProSe application mask Mm and ProSe application code A in aRAC of the ProSe application ID would be added to discovery filter F.

On the other hand, the processing module 254_1 may generate a seconddiscovery code combination of the allowed user and assigning the ProSeapplication code of the monitoring UE and a second ProSe applicationmask in the second discovery code combination in response to the firstdiscovery code combination of the allowed user corresponding to theProSe application ID being not available. For example, the processingmodule 254_1 may create a new RAC and RAPAP for an allowed user W. Then,ProSe application mask Mm and ProSe application code A in the createdRAC would be added to the discovery filter F. Then, the created RACwould be updated and corresponding to ProSe application ID contained inthe Discovery Request message to RAPAM of the allowed user W. Then, alldiscovery filters Fs would be assign to the monitoring UE.

It should be noticed that, there may have many allowed user in theallowed user list S_(allowed), and each allowed user would becorresponding to one discovery filter F. This may cause too manydiscovery filters Fs assigned to the monitoring UE. Since one discoveryfilter may include more than one discovery mask, thus unnecessarydiscovery filter F could be removed.

In one embodiment of the present disclosure, the processing module 254_1may merge a first discovery filter and a second discovery filter in thediscovery filter in response to a ninth ProSe application code of themonitoring UE in the first discovery filter matches a third ProSeapplication mask and a tenth ProSe application code in the seconddiscovery filter. Specifically, it is defined that a set of assigneddiscovery filters as F_(set), and ProSe application mask assigned todiscovery filter F as Mm1. It is assumed that the ProSe application codeof announcing UE from the same restricted announcing combination (RAC)as Mm1 is Pr1. In following description, it is defined this kind ofProSe application code of announcing UE as “announcing ProSe code ofdiscovery filter”. For example, Pr1 is the announcing ProSe code offilter F.

It is assumed that ProSe application code A2 is assigned to one of thediscovery filter G. A match equation would be defined as equation (1):(Pr1&Mm1)=(A2&Mm1)  (1)Where Pr1, Mm1, and A2 are bit strings with the same length such as 5,10, 15, etc. “&” is a bitwise AND operation. ProSe application code A2is matched with ProSe application code Pr1 and ProSe application maskMm1 if satisfying the equation (1). On the other hand, ProSe applicationcode A2 is not matched with ProSe application code Pr1 and ProSeapplication mask Mm1 if not satisfying the equation (1) (i.e. (Pr1 &Mm1)is not equal to (A2&Mm1)). Then, a discovery filter F would be removedif ProSe application mask Mm1 of the discovery filter F can satisfy theequation (1).

In response to the first ProSe application code of the monitoring UE inthe first discovery filter matching the third ProSe application mask andthe tenth announcing ProSe application code in the second discoveryfilter, the processing module 254_1 may assign the third ProSeapplication mask in the second discovery filter to the first discoveryfilter, and delete the second discovery filter. For example, ProSeapplication mask Mm1 of the discovery filter F would be added todiscovery filter G, and this discovery filter F would be destroyed frommemory module 254_2. On the other hand, in response to the ninth ProSeapplication code of the monitoring UE in the first discovery filter notmatching the third ProSe application mask and the tenth announcing ProSeapplication code in the second discovery filter, the second discoveryfilter would be kept. For example, the discovery filter F would be keptin memory module 254_2. After checking every discovery filter G in theset of discovery filters Fs_(et), if discovery filter F is stillavailable, this discovery filter F would be added to the set ofdiscovery filters Fs_(et). Then, all discovery filters in the set ofdiscovery filters Fs_(et) would be added to Discovery Response message.

In addition, the allowed user list S_(allowed) may be stored in thememory module 254_2 or obtained from APP server 290 or other third partserver. In one embodiment of the present disclosure, the processingmodule 254_1 may transmitting a list request message comprising theProSe application ID and an application layer user ID of the UE identitythrough the transmitting module 254_5 in response to receiving thediscovery request message, and receiving a list response messagecomprising an allowed user list corresponding the ProSe application IDand the application layer user ID through the receiving module 254_7 inresponse to the list request message.

Specifically, the processing module 254_1 would find ALUID correspondingto UE identity contained in Discovery Request message, and transmit listrequest message comprising the ProSe application ID indicating thetarget group of the UE identity and the ALUID (or UE identity) to APPserver 290 through the transmitting module 254_5. Based on themonitoring UE's discovery configuration, APP server 290 would find outall allowed users that are allowed to discover this monitoring UE, andfill all allowed users to an allowed user list S_(allowed). Then, theallowed user list S_(allowed) contained in the list response messagewould be forward to network entity 254. It should be noticed that, thelist request message and list response message could be any PC2 controlmessage.

In step S950, the processing module 254_1 may transmit a discoveryresponse message comprising the discovery code through the transmittingmodule 254_5 in response to the discovery request message. In theannounce request procedure which is consistent with 3GPP TS 23.303 andTS 24.334, Discovery Response message would be transmitted to theannouncing UE such as UE 210. In the monitoring request procedure whichis consistent with 3GPP TS 23.303 and TS 24.334, Discovery Responsemessage would be transmitted to the monitoring UE such as UE 220. Thediscovery response message would comprise all discovery filters whichare obtained in step S950. Accordingly, ProSe application code of thediscovery code contained in PC5 Discovery message would be announced foropen discovery or restricted discovery by the announcing UE, anddiscovery filter of the discovery code would use to check whether thematch event occurs by the monitoring UE.

In order to help those skilled in the art to understand how the proposedmethods of proximity discovery are processed in the communication system200 according to the embodiments of the present disclosure, thefollowing would provide an example.

In the first example, FIG. 10 illustrates a signaling diagram of amonitor request process in accordance with one of the exemplaryembodiment of the present disclosure. In step S1011, monitoring UE 1012transmits a Discovery Request comprising ProSe application IDAPPID_FB_Family to ProSe function 1074. ProSe function 1074 transmitslist request message comprising ALUID corresponding to monitoring UE1012 and ProSe application ID APPID_FB_Family to APP server 1090, to askfor an allowed user list S_(allowed) (S1013). In step S1015, APP server1090 would trace requested ProSe application ID APPID_FB_Family. Allowedusers which are allowed to discover monitoring UE 1012 are collected inthe allowed user list S_(allowed). In step S1016, the allowed user listS_(allowed) would be transmitted to ProSe function 1074. Then, ProSefunction 1074 would assign discovery filters Fsor each allowed user inthe allowed user list S_(allowed) (S1017).

Table (2) is RAPAM of UE H in the allowed user list S_(allowed). Therequested ProSe application ID APPID_FB_Family is in the RAPAM of UE H.Then, ProSe application code A3 and ProSe application mask Mm3 in RAC3would be add to discovery filter F of Monitoring UE.

TABLE (2) ProSe application ID RAC APPID_FB_Family RAC3 APPID_TwitterRAC4

Table (3) is RAPAM of UE K in the allowed user list S_(allowed). Therequested ProSe application ID APPID_FB_Family is not in the RAPAM of UEK. Then, referring to table (4) which is updated RAPAM of UE K, RAC6corresponding to ProSe application ID APPID_FB_Family would be created,and ProSe application code A6 and ProSe application mask Mm6 would inRAC6 would be add to discovery filter F of Monitoring UE.

TABLE (3) ProSe application ID RAC APPID_GTalk RAC5

TABLE (4) ProSe application ID RAC APPID_GTalk RAC5 APPID_FB_Family RAC6

In step S1018, all generated discovery filters Fs would be added toDiscovery Response message. Part of generated discovery filters Fs maybe merged. Then, the Discovery Response message comprising discoveryfilters Fs would be transmitted to monitoring UE 1012 (S1019).

In view of the aforementioned descriptions, the present disclosureprovides a method of performing proximity discovery for a network entityand a UE. In the proposed signalling message flows for restricteddiscovery, an announcing UE would directly receive PC5 discoveryresponse message in response to the PC5 discovery message over PC5interface without negotiating with ProSe function. In addition, theaforementioned embodiments provide assignment and maintenance ofdiscover codes such as ProSe application code of announcing UE anddiscovery filter of monitoring UE for open discovery and restricteddiscovery. The ProSe application ID would indicate target group which isinterest to discover or to be discovered. The proposed method would notchange the existing network structure, and would not bring muchprocessing or management loading of ProSe function.

It should be noted that the adjectives “first”, “second”, “third”, andso forth are simply used to distinguish one item or object from anotherand thus may or may not imply a sequence of events.

No element, act, or instruction used in the detailed description ofdisclosed embodiments of the present application should be construed asabsolutely critical or essential to the present disclosure unlessexplicitly described as such. Also, as used herein, each of theindefinite articles “a” and “an” could include more than one item. Ifonly one item is intended, the terms “a single” or similar languageswould be used. Furthermore, the terms “any of” followed by a listing ofa plurality of items and/or a plurality of categories of items, as usedherein, are intended to include “any of”, “any combination of”, “anymultiple of”, and/or “any combination of” multiples of the items and/orthe categories of items, individually or in conjunction with other itemsand/or other categories of items. Further, as used herein, the term“set” is intended to include any number of items, including zero.Further, as used herein, the term “number” is intended to include anynumber, including zero.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentdisclosure without departing from the scope or spirit of the disclosure.In view of the foregoing, it is intended that the present disclosurecover modifications and variations of this disclosure provided they fallwithin the scope of the following claims and their equivalents.

What is claimed is:
 1. A method of performing proximity discovery, usedby a network entity, the method comprising: receiving a discoveryrequest message comprising a Proximity-based Services (ProSe)application identifier (ID) and a User Equipment (UE) identity, whereinthe ProSe application ID indicates a target group of the UE identity;obtaining a discover code for performing the proximity discoveryaccording to the ProSe application ID by assigning a ProSe applicationcode according to a discovery combination of an announcing UEcorresponding to the target group of the UE identity in response toobtaining the ProSe application code for a restricted discovery, whereinthe discover code is the ProSe application code of the announcing UE,and the discovery code combination comprises the ProSe application codeof the restricted discovery, a ProSe application code of a monitoringUE, and a ProSe application mask; and transmitting a discovery responsemessage comprising the discovery code in response to receiving thediscovery request message.
 2. The according to claim 1, whereinassigning the ProSe application code according to the discovery codecombination of the announcing UE corresponding to the target group ofthe UE identity in response to obtaining the ProSe application code forthe restricted discovery comprising: obtaining the ProSe applicationcode from the discovery code combination in response to the discoverycode combination corresponding to the ProSe application ID beingavailable.
 3. The according to claim 1, wherein assigning the ProSeapplication code according to the discovery code combination of theannouncing UE corresponding to the ProSe application ID in response toobtaining the ProSe application code for the restricted discoverycomprising: generating a first discovery code combination and assigninga first ProSe application code in the first discovery code combinationas the ProSe application code in response to the discovery codecombination corresponding to the ProSe application ID being notavailable.
 4. The method according to claim 1, wherein the discover codecomprises a discovery filter of the monitoring UE, and obtaining thediscover code for performing the proximity discovery according to theProSe application ID comprising: assigning the ProSe application code ofthe monitoring UE and the ProSe application mask to the discovery filteraccording to the discovery code combination of an allowed user in thetarget group, respectively.
 5. The method according to claim 4, whereinassigning the ProSe application code of the monitoring UE and the ProSeapplication mask to the discovery filter according to the discovery codecombination of the allowed user in the target group comprising:obtaining a first ProSe application code of the monitoring UE and afirst ProSe application mask from a first discovery code combination ofthe allowed user in the discovery code combination in response to thefirst discovery code combination of the allowed user corresponding tothe ProSe application ID being available.
 6. The method according toclaim 5, wherein assigning the ProSe application code of the monitoringUE and the ProSe application mask to the discovery filter according tothe discovery code combination corresponding to the ProSe application IDcomprising: generating a second discovery code combination of theallowed user and assigning a second ProSe application code of themonitoring UE and a second ProSe application mask in the seconddiscovery code combination in response to the first discovery codecombination of the allowed user corresponding to the ProSe applicationID being not available.
 7. The method according to claim 4, whereintransmitting the discovery response message comprising the discoverycode in response to the discovery request message comprising:transmitting the discovery response message comprising all discoveryfilters.
 8. The method according to claim 1, wherein after the step ofreceiving the discovery request message comprising the ProSe applicationID and the UE identity, the method further comprising: transmitting alist request message comprising the ProSe application ID and anapplication layer user ID of the UE identity in response to receivingthe discovery request message; and receiving a list response messagecomprising an allowed user list corresponding the ProSe application IDand the application layer user ID in response to the list requestmessage.
 9. The method according to claim 8, wherein the discover codecomprises a discovery filter of the monitoring UE, the allowed user listcomprises allowed application layer user IDs of allowed users, andobtaining the discover code of the proximity discovery according to thetarget group of the UE identity comprising: obtaining the discoveryfilter for the allowed users.
 10. The method according to claim 4,wherein obtaining the discover code of the proximity discovery accordingto the ProSe application ID further comprising: merging a firstdiscovery filter and a second discovery filter in the discovery filterin response to a second ProSe application code of the monitoring UE inthe first discovery filter matches a third ProSe application mask and athird ProSe application code in the second discovery filter.
 11. Themethod according to claim 10, wherein after the step of merging thefirst discovery filter and the second discovery filter in the discoveryfilter, the method further comprising: assigning the third ProSeapplication mask in the second discovery filter to the first discoveryfilter; and deleting the second discovery filter.
 12. The methodaccording to claim 11, further comprising: determining the firstannouncing ProSe application code of the first discovery filter as beingmatched with the third ProSe application mask and the third ProSeapplication code in the second discovery filter in response to a firstbitwise AND operation output between the third ProSe application codeand the third ProSe application mask in the second discovery filter asbeing matched with a second bitwise AND operation output of the firstannouncing ProSe application code of the first discovery filter and thethird ProSe application mask in the second discovery filter; anddetermining the first announcing ProSe application code of the firstdiscovery filter as being not matched with the third ProSe applicationmask and the third ProSe application code in the second discovery filterin response to the first bitwise AND operation output between the thirdProSe application code and the third ProSe application mask in thesecond discovery filter as being not matched with the second bitwise ANDoperation output of the first announcing ProSe application code of thefirst discovery filter and the third ProSe application mask in thesecond discovery filter.
 13. The method according to claim 11, whereinthe network entity is one of a ProSe function and a server.